This invention relates to a marking for painted objects, wherein characteristics of the paint coat are used for the marking, and to a method for marking painted objects in which a paint coat which preferably has several paint layers is applied to the object and wherein characteristics of the paint coat are used for marking the object. According to the present invention, such markings can be used for motor vehicles.
Published German Patent Application DE 43 35 308 A1 discloses a marking for motor vehicles which is intended to make motor vehicle thefts more difficult and to thereby discourage them. According to DE 43 35 308 A1, the marking is hard to remove and can easily be identified. The marking takes place by applying special information to constituents of a coding layer of the paint coat, wherein the coding corresponds to pigments. The pigments, which are smaller than the mm-range, do not interfere with the appearance of the paint coat. However, the application of the marking is very expensive, particularly for motor vehicles, because each marking can only be applied to one vehicle. Additionally, the marking of older vehicles is very expensive. Repainting, which might be necessary after a repair for example, is also expensive, especially as the marking is to remain and retain its significance in the freshly painted areas.
German Patent Document DE 34 45 401 A1 discloses another marking for motor vehicles where, in the case of a multi-layer paint coat, a coding layer provided with a marking is arranged under a paint layer. In the visible spectral range, the paint layer has a reflective characteristic. In a wave length range outside the visible spectrum, in which the viewing of the marking of the coding layer is to take place, the paint layer is transparent. However, a disadvantage exists in that during the painting, the application of an additional layer, specifically a coding layer, and its subsequent coding is necessary. In addition, retouching the paint in the case of an accident is also expensive.
It is an object of the present invention to provide a marking that can be simply applied during the manufacture of objects to be marked. Furthermore, it is an object of the present invention to provide a method for applying a marking which is useful to recode older objects as well as to recode repaired objects.
The marking according to the present invention is characterized in that, in a measuring range of electromagnetic waves which is arranged within the electromagnetic spectrum of the paint coat, the paint coat has a largely constant spectral electromagnetic partial spectrum which, at certain frequencies, has narrow-band extremes of at least 5% relative intensity change. The method according to the present invention is characterized in that the spectral course of the partial spectrum of the electromagnetic spectrum of the paint coat arranged within an electromagnetic measuring range, is changed in a targeted manner such that it has narrow-band extremes of at least 5% relative intensity change.
As a result of the targeted introduction of narrow-bands and abrupt changes at defined frequencies within a measuring range of the electromagnetic spectrum of the paint coat, a specific code used for marking can be assigned to any painted object, particularly any motor vehicle, and the coding can take place in a simple manner. A further advantage is that older objects can also be marked without any significant change of the color impression of the paint coat.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.